CVE-2026-72859: Incorrect Authorization in budibase server
Budibase versions 3.39.4 before 3.40.0 contain an authorization regression in the S3 attachment upload endpoint that allows BASIC users to obtain S3 PutObject presigned URLs by sending POST requests to the attachments endpoint. The route was changed from a BUILDER permission check to a TABLE/WRITE check, which BASIC users hold by default. Attackers can specify arbitrary S3 buckets in the request body to generate presigned URLs for writing to any bucket accessible by the stored IAM credentials, enabling unauthorized file uploads.
AI Analysis
Technical Summary
In Budibase server version 3.39.4, an authorization regression exists in the S3 attachment upload endpoint. The permission check was changed from requiring BUILDER permissions to a TABLE/WRITE check, which BASIC users have by default. This flaw allows BASIC users to send POST requests to the attachments endpoint specifying arbitrary S3 buckets in the request body, generating presigned URLs for writing files to any bucket accessible by the IAM credentials stored by the server. This enables unauthorized file uploads to potentially any S3 bucket accessible by the server's credentials.
Potential Impact
An attacker with BASIC user privileges can upload files to arbitrary S3 buckets accessible by the server's IAM credentials without proper authorization. This could lead to unauthorized data uploads, potential data corruption, or abuse of storage resources. The vulnerability has a high severity with a CVSS 4.0 score of 8.3, indicating significant impact if exploited.
Mitigation Recommendations
A patch is available for this vulnerability. Since Budibase server is a cloud service, the vendor manages remediation server-side. Users should verify with the vendor advisory that their service instance has been updated to version 3.40.0 or later where this issue is fixed. No additional mitigation actions are required if the patch is applied.
CVE-2026-72859: Incorrect Authorization in budibase server
Description
Budibase versions 3.39.4 before 3.40.0 contain an authorization regression in the S3 attachment upload endpoint that allows BASIC users to obtain S3 PutObject presigned URLs by sending POST requests to the attachments endpoint. The route was changed from a BUILDER permission check to a TABLE/WRITE check, which BASIC users hold by default. Attackers can specify arbitrary S3 buckets in the request body to generate presigned URLs for writing to any bucket accessible by the stored IAM credentials, enabling unauthorized file uploads.
CVSS v4.0
Score 8.3high
Affected software
Run on your own infrastructure? Check whether these packages are installed with threat-finder — our free open-source scanner.
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
In Budibase server version 3.39.4, an authorization regression exists in the S3 attachment upload endpoint. The permission check was changed from requiring BUILDER permissions to a TABLE/WRITE check, which BASIC users have by default. This flaw allows BASIC users to send POST requests to the attachments endpoint specifying arbitrary S3 buckets in the request body, generating presigned URLs for writing files to any bucket accessible by the IAM credentials stored by the server. This enables unauthorized file uploads to potentially any S3 bucket accessible by the server's credentials.
Potential Impact
An attacker with BASIC user privileges can upload files to arbitrary S3 buckets accessible by the server's IAM credentials without proper authorization. This could lead to unauthorized data uploads, potential data corruption, or abuse of storage resources. The vulnerability has a high severity with a CVSS 4.0 score of 8.3, indicating significant impact if exploited.
Mitigation Recommendations
A patch is available for this vulnerability. Since Budibase server is a cloud service, the vendor manages remediation server-side. Users should verify with the vendor advisory that their service instance has been updated to version 3.40.0 or later where this issue is fixed. No additional mitigation actions are required if the patch is applied.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- VulnCheck
- Date Reserved
- 2026-08-10T15:16:31.372Z
- Cvss Version
- 4.0
- State
- PUBLISHED
- Remediation Level
- null
- Is Cloud Service
- true
Threat ID: 6a7f0286bf8831d539fec913
Added to database: 08/14/2026, 11:56:54 UTC
Last enriched: 08/14/2026, 12:11:06 UTC
Last updated: 08/14/2026, 16:55:21 UTC
Views: 7
Community Reviews
0 reviewsCrowdsource mitigation strategies, share intel context, and vote on the most helpful responses. Sign in to add your voice and help keep defenders ahead.
Want to contribute mitigation steps or threat intel context? Sign in or create an account to join the community discussion.
Actions
Updates to AI analysis require Pro Console access. Upgrade inside Console → Billing.
Need more coverage?
Upgrade to Pro Console for AI refresh and higher limits.
For incident response and remediation, OffSeq services can help resolve threats faster.
Latest Threats
Check if your credentials are on the dark web
Instant breach scanning across billions of leaked records. Free tier available.